Mannitol metabolism in plants: A method for coping with stress

Mannitol, a six carbon sugar alcohol, has heretofore received little attention from plant scientists, despite its wide distribution in nature. However, recent findings concerning the biochemistry and physiology of higher plants indicate that species that metabolize mannitol have several advantages over those that exclusively translocate sugars. One advantage is increased tolerance to salt- and osmotic-stress as a result of mannitol's function as a 'compatible solute'. Another advantage is a possible role in plant responses to pathogen attack - thus mannitol metabolism may play roles in plant responses to both biotic and abiotic stresses.